Life and Annuity Benefits (Liability for Future Policy Benefit, Activity) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]
Liability for future policyholder benefits, beginning of year		$ 557,763	$ 554,366
Liability for future policyholder benefits at original discount rate, beginning of year		642,877	667,761
Effect of changes in cash flow assumptions				$ 0	$ 0
Effect of actual variances from expected experience				(4,745)	$ (5,890)
Adjusted liability for future policyholder benefits, beginning of year		638,132	661,871
Interest accretion		10,596	11,251
Benefit payments		(37,083)	(39,819)
Effect of foreign currency changes		4,450	(356)
Liability for future policy holder benefits t original discount rate, end of period		616,095	632,947
Cumulative effect of changes in discount rate assumptions		(82,700)	(124,511)
Liability for future policyholder benefits, beginning of year, ending of period	[1]	533,395	$ 508,436
Undiscounted liability for future policyholder benefits		$ 787,600		$ 813,600

[1] The undiscounted liability for future policyholder benefits was $787.6 million and $813.6 million as of September 30, 2024 and 2023, respectively.